Dampened railway car truck

ABSTRACT

This invention relates to a railway vehicle suspension in which the vehicle is supported on wheelsets or double axle bogies by way of a yaw suspension which allows relative yawing movements between the vehicle and the wheelsets or bogies. This yaw suspension includes a resilient arrangement, such as a seriesconnected damper and spring, whose dynamic stiffness increases with increase in the yaw velocity. In this way any high frequency yawing movements, such as are caused by track irregularities, are quickly damped out.

Unite States Hobbs DAMPENED RAILWAY CAR TRUCK Anthony Edward WalterHobbs, London, England Assignee: Briti sh Railways Board, London,

England Filed: Sept. 15, 1969 Appl. No.: 858,093

Inventor:

References Cited UNITED STATES PATENTS 2/1937 Hanna ..l05/82 6/1944Travilla, Jr.....l ..105/199 R 3/1949 Dean ..105/199 R 12/1964Grossnickle....-....105/199 R X [451 Sept. 12, 1972 3,376,831 4/1968Eaton et al ..l05/l97 D X 2,907,283 10/1959 Markestein et al.105/182'R X3,020,857 2/1962 Dean ..l05/ 199 R 1,256,558 2/1918 Hild ..l05/l99 X2,915,020 12/1959 Bleibtreu 105/4 9/1970 Wickens 105/1 82 PrimaryExaminer-Arthur L. La Point Assistant Examiner-Howard BeltranAttorney-Sommers & Young [57] ABSTRACT This invention relates to arailway vehicle suspension in which the vehicle is supported onwheelsets or double axle bogies by way of a yaw suspension which allowsrelative yawing movements between the vehicle and the wheelsets orbogies. This yaw suspension in cludes a resilient arrangement, such as aseries-connected damper and spring, whose dynamic stiffness increaseswith increase in the yaw velocity. In this way any high frequency yawingmovements, such as are caused by track irregularities, are quicklydamped out.

7 Claims, 4 Drawing Figures PATENTEDSEP 12 m2 SHEET 1 OF 2 FIG! ANTHONY.W. HOBBS DAMPENED RAILWAY CAR TRUCK This invention relates to railwayvehicles, and in particular toyaw suspensions thereof.

Yaw suspensions are provided in railway vehicles to permit yawing, thatis relative rotation of the vehicle body and the wheelset about avertical axis, against a resilient restraint. I

This invention is applicable 'to yaw suspensions which are directlybetween the wheelset and the vehicle body or between a bogie frame andthe vehicle body or between the wheelsets and a bogie frame. Hence it isapplicable to freight and passenger vehicles whether of two axle, bogieor other. configuration.

According to the invention,the yaw suspension includes a resilientarrangement whose dynamic stiffness increases with increase in yawvelocity. Thus the yaw suspension can be arranged, on the one hand, topermit substantially unrestrained yawing at low yawing velocities suchas are encountered when 3 the vehicle negotiates a curve'in the track sothat the wheelsets remain radially aligned tothe track curvature, and,on

I the other hand, to provide an appropriate dynamic stiffnessito ensuredynamic stability to track irregularities which produce high yawingvelocities in the nature of high frequency oscillation so that theamplitude of this oscillation is small.

The resilient arrangement of the yaw suspension may comprise a hydraulicdamper and spring in series and, optionally, a further spring can beprovided in parallel with the series-connected damper and spring.

Preferred embodiments of the present invention will now be describedwith reference to the accompanying diagrammatic drawings in which:

FIG. 1 is a plan view of a yaw suspension connected between a singleaxle wheelset and the vehicle body.

F lG.y2 is a plan view of a second arrangement where a yaw suspension isconnected between a two axle bogie and the vehicle body.

FIG. 3 is a side view of a third arrangement where a yaw suspension isconnected. between a pair of single axle wheelsets and a geometricallysteered member secured at its outer ends to adjacent coaches. of thevehicle.

FIG. 4 is a partial plan view of the arrangement shown in FIG. 3.

In. FIG. 1 a single axle wheelset is rotatably mounted at its outer endsin axle boxes 11. The axle boxes 11 support a vehicle body by a suitablesuspen sion (not shown) which allows vertical, lateral and yawingmovements between the wheelset and the body.

A hydraulic damper 12 connected in series with a spring 13 isconnectedbetween each of the axle boxes 11 and the vehicle bodywork 14.The longitudinal axes of each of the dampers l2 and springs 13 arearranged to be as near horizontal as possible. I

The characteristics of the dampers 12 are arranged such thatsubstantially no restraint is offered to low frequency yawing movementsof the wheelset relative to the body, such as occur when the railwayvehicle is negotiating a curve in the track. In this situation, thewheelset is permitted to yaw so as to take up a position in which theaxle axis lies substantially radially to the curve. On the other hand,any high-frequency yawing movements, caused for example by trackirregularities, are quickly damped out by the high resistance offered bythe dampers 12 to any such high-frequency movements.

'The springs 13 can be of any convenient type, and their stiffness ischosen in accordancewith the mass of the wheelset to be controlled. Asecond auxiliary spring 15 may be connected in parallel with the damperl2 and spring 13. This spring 15 will normally be of lesser stiffnessthan The spring 13 and is included for stability purposes.

FIG. 2 illustrates a corresponding arrangement in which a pair ofwheelsets 10 are mounted in a bogie frame consisting of a pair oflongitudinal members 16, interconnecting the axle boxes 11 of the twowheelsets, and a central transverse member 17. The member 17 is rigidlyconnected to the longitudinal member 16. The vehicle body is supportedon the bogie frame by a vertical and lateral suspension (not shown)which allows the bogie to yaw relative to the body about the centerpoint of the transverse member 17. The series-connected dampers l2 andsprings 13 are in'this embodiment connected between the outer ends ofthe transverse member 17 and the vehicle body 14.

The operation of the dampers 12 is exactly as described with referenceto FIG. 1 in that no resistance is offered to any low frequency yawingmovement of the bogie relative to the body, whilst high frequency yawingmovements are quicklydamped out.

In FIG. 3, an arrangement is shown in which adjacent coaches 18 and 19of the train are joined by a central pivotal joint 20. A steering beam21 extends across this joint 20 between the two coaches 18 and Y19 andis connected at its ends to the coach bodies by pin joints or othersuitable joints 22. This type of connection between vehicle bodies isfully described in co-pending application Ser. No. 849,322, filed Aug.12, I969, and now abandoned and superseded by continuation-inpartapplication ser. No. 129,899, filed Mar. 31, I971.

Traction rods 23 are connected between the axle boxes 24 at each end ofa pair of wheelsets 25 and 26, and one end of a pair of pivoted beams27. These beams 27 are pivotally mounted on the steering beam 21 byjoints 28 so as to allow the beam 27 and hence the wheelsets 25 and 26to yaw relative to the steering beam. This yawing movement is controlledby means of a pair of hydraulic dampers 29 and springs 30 connected inseries between the ends of the beam 27 and arms 31 extending laterallyfrom the steering beam 21. The operation of the combined dampers 29 andsprings 30 is to damp out any high frequency yawing movements of thewheelsets 25 and 26 relative to the steering beam 21. As with theembodiments shown in FIGS. 1 and 2, a second spring may be connected inparallel to each series-connected damper 29 and spring 30. A verticalsuspension is shown diagrammatically by the elements 33, 34, 35 and 36,although it will be understood that any conventional type of verticalsuspension means may be employed instead of that shown.

The arrangement shown in FIGS. 3 and 4, in which a pair of wheelsets areindependently mounted from the steering beam 21, is equally applicableto an arrangement in which a double axle bogie is mounted on the beam21. This arrangement is similar to that described with reference to FIG.2 except that the bogie frame is mounted on the-steering beam andtheseries connected dampers and springs are connected between the frame andthe steering beam.

Iclaim:

l. A railway vehicle including a supporting member, a wheelset, yawsuspension means operatively connecting said wheelset to said supportingmember so as to permit yawing movements relative thereto, said yawsuspension means including resilient means which resists motion about ayaw axis between said wheelset and said supporting member and having adynamic stiffness which increases with increase in the yaw velocity,whereby high frequency yawing oscillations of the wheelset relative tothe supporting member are quickly damped without imparing the lowfrequency yawing movements of the wheelset.

2. A railway vehicle as claimed in claim 1 wherein said resilient meanscomprises a damper and a spring connected in series.

3. A railway vehicle as claimed in claim 1 which further includes avehicle body and wherein two said wheelsets are arranged as a doubleaxle bogie which includes a bogie frame, said yaw suspension means beingconnected between said bogie frame and the vehicle body.

4. A railway vehicle as claimed in claim 1 which further includes avehicle body and wherein two said wheelsets are arranged as a doubleaxle bogie which includes a bogie frame, said yaw suspension means beingconnected between said bogie frame and the vehicle body.

5. A railway vehicle as claimed in claim 1 wherein said supportingmember is a rigid beam extending across the interconnection between twoadjacent vehicle bodies and which is connected at its ends to the twovehicle bodies at a distance longitudinally of the vehicle bodies fromtheir interconnection with each other, said yaw suspension beingconnected between said rigidbeam and at least one wheelset mounted onsaid beam.

6. A railway vehicle as claimed in claim 5 wherein a second beam isprovided, extending transversely of the rigid beam and pivotally mountedthereon so as to be able to yaw relative thereto, the wheelset beingconnected to said second beam such that the second beam follows allyawing movements of the wheelset relative to the rigid beam and whereinthe yaw suspension is connected between the second beam and said rigidbeam.

7. A railway vehicle as claimed in claim 5 wherein two wheelsets aremounted on said beam, each independently of the other.

1. A railway vehicle including a supporting member, a wheelset, yawsuspension means operatively connecting said wheelset to said supportingmember so as to permit yawing movements relative thereto, said yawsuspension means including resilient means which resists motion about ayaw axis between said wheelset and said supporting member and having adynamic stiffness which increases with increase in the yaw velocity,whereby high frequency yawing oscillations of the wheelset relative tothe supporting member are quickly damped without imparing the lowfrequency yawing movements of the wheelset.
 2. A railway vehicle asclaimed in claim 1 wherein said resilient means comprises a damper and aspring connected in series.
 3. A railway vehicle as claimed in claim 1which further includes a vehicle body and wherein two said wheelsets arearranged as a double axle bogie which includes a bogie frame, said yawsuspension means being connected between said bogie frame and thevehicle body.
 4. A railway vehicle as claimed in claim 1 which furtherincludes a vehicle body and wherein two said wheelsets are arranged as adouble axle bogie which includes a bogie frame, said yaw suspensionmeans being connected between said bogie frame and the vehicle body. 5.A railway vehicle as claimed in claim 1 wherein said supporting memberis a rigid beam extending across the interconnection between twoadjacent vehicle bodies and which is connected at its ends to the twovehicle bodies at a distance longitudinally of the vehicle bodies fromtheir interconnection with each other, said yaw suspension beingconnected between said rigid beam and at least one wheelset mounted onsaid beam.
 6. A railway vehicle as claimed in claim 5 wherein a secondbeam is provided, extending transversely of the rigid beam and pivotallymounted thereon so as to be able to yaw relative thereto, the wheelsetbeing connected to said second beam such that the second beam followsall yawing movements of the wheelset relative to the rigid beam andwherein the yaw suspension is connected between the second beam and saidrigid beam.
 7. A railway vehicle as claimed in claim 5 wherein twowheelsets are mounted on said beam, each independently of the other.